As automobile paintwork continues to thin, these tools are essential for anyone touching up or polishing paintwork. As people keep cars longer, it is equally important to determine if the car has previously been aggressively polished. You don't want to be the type to burn thin polish. Finally, when buying a used vehicle, you want to identify an undisclosed paint job or repair. In all these cases, this device copes with the work without much effort. I have used and used several paint thickness gauges. Like most under $500, it uses electromagnetism to determine the overall depth of the coating on the metal. It does not work on plastic and does not distinguish the individual depth of multiple coatings such as primer, paint, varnish. This performance level reaches the 4-digit mark for ultrasonic devices. For the average detailer or painter, these devices are all you need. When I opened the box I was pleased to see that a good carrying case was included in the packaging. Some devices only have one box. It also includes instructions and calibration materials (aluminum, steel, and reference substrates of various thicknesses). Requires 2 AAA batteries, not included. For such devices, I prefer standard batteries to built-in ones because I don't have to worry about them staying charged or the battery dying after a few years. Calibration is pretty easy. As with other devices, you calibrate steel and aluminum separately. After this was done, I also tested the substrates from another device with a different thickness. I was happy to see that they were all within 1%, with occasional deviations from readings. I compared some measurements on the car with a more expensive device and was again impressed with the accuracy. This is the most important attribute and that's why I can recommend this device, especially in this price range. Some features you don't get at this price include limited configuration options. While you can see mils, ums, or mms, you have to cycle through them. You cannot set a default value or option to display multiple measurement types. It doesn't give noisy readings, which comes in handy when you're taking multiple readings in the car. No cons here either, just features you can pay more for if they're important to you. For an easy-to-use device that gives accurate readings without spending a fortune, this is a winner.